Engine starting mechanism



Jan. 26, 1943. c. A. NERACHER ET AL 2,309,413

v ENGINE STARTINGflfiECHANISM Filed April 10, 1940 I 2 Sheets-Sheet l INVENTORS.

A TTOR NE Y5.

Jan. 26, 1943. c. A. NERACHER ET AL ENGINE STARTlNG MECHANISM 2 She ets-Sheet 2 Filed April 10, 1940 INVENTORS.

V AWoRNu-s.

Patented Jan. 26, 1943 ENGINE STARTING MECHANISM Carl A. Neracher and William T. Dunn, Detroit,

Mich, assignors to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware Application April 10, 1940, Serial No. 328,858 Q 8 Claims.

This application relates to engine starting devices and is a continuation-impart of our copending application, Serial No. 271,016, filed May 1, 1939.

The invention disclosed and claimed herein is concerned with improvements in engine starting devices generally and is particularly concerned with improvements in starting devices intended for use with engines used with fluid torque transmitters such as those commonly known in the art as fluid couplings, fluid drives," "liquid drives," fluid torque converters, etc.

Heretofore, it has been customary in motor vehicles embodying fluid couplings to mount the ring gear, with which the starter pinion is adapted to mesh, on the coupling housing. Such an arrangement is shown in U. S. Patent No. 2,182,407, issued to A. J. Phelan et al. on December 5, 1939. There are certain disadvantages in such an arrangement which our invention avoids.

For instances, in arrangements like that shown in the aforesaid Phelan patent, it is necessary to replace the entire fluid coupling assembly should the ring gear become damaged (which frequently occurs due to accidental engagement of the starter pinion therewith during operation of the engine) because the ring gear is welded to the coupling housing and cannot be removed without damage to the housing. In addition, the ring gear increases the diameter of the rotating assembly at a point where space is at a premium and the starting motor is required to be mounted in a place that makes servicing awkward.

It is therefore the principal object of the invention to provide a structure in which the starter ring gear can be mounted at a more accessible and convenient location.

A further object is to provide a starting system for vehicles employing fluid couplings and .the-

like in which damage to the starter ring gear will not require removal of the coupling structure.

A still further object is to provide a starting system which is more compact than those known in the art.

A still further object is to provide an engine starting system during operation of which shocks incident to engagement of the starting pinion, etc., are eflectively cushioned.

Still another feature of our invention resides in the provision of means for permitting the engine to be started through the fluid coupling thereby permitting the utilization of a starting motor of higher speed and smaller size than those now in common use, which type of motor is lighter in weight and cheaper and, because of inherent slip in the coupling, will not draw the heavy surge of current from the vehicle battery which is usually necessary to break the static friction incidental to starting a heavy engine.

Additional objects and advantages of our invention will become apparent from the following description taken in conjuction with the accom panying drawings which are illustrative of two of the many possible embodiments of the inven-- tion.

Referring ,to the drawings in which like reference numerals designate corresponding parts referred to herein;

Fig. l is a longitudinal vertical sectional view of a portion of a vehicle driving mechanism embodying the present invention.

Fig. 2 is a similar view of a modified form of the invention embodied in a different driving arrangement, and

Fig. 3 is a sectional view along the line 3--3 of Fig. 2.

Referring to Fig. 1 of the drawings, reference numeral i0 designates the crankshaft of the internal combustion engine to which is attached by suitable fastening means Ii the impeller I! of a fluid coupling designated generally by the letter A. The impeller i2 is provided with the usual vanes i3 and shroud member H which forms a housing for the coupling assembly, a suitable seal i5 being provided to insure a fluid tight connection between the coupling housing and the output shaft which wil1 be referred to later on.

The fluid coupling A is also provided with arunner member it provided with the usual vanes ll which is carried by a hub l8 splined at 20 on a hollow shaft i9. An antifriction bearing 2i supports the hub I 8 within the hollowed out portion 22 of the crankshaft i0. Hollow shaft i9 is provided at its rearward end with an enlarged portion 23 which'forms the housing of a fluid cylinder 24 containing a slidable piston 25. The aforesaid enlarged portion 23 of the shaft i9 carries a clutch spider 26 which is splined thereto at 21. The clutch spider 26 referred to generally by the numeral 28 which is adapted to be engaged and disengaged under the influence of the piston 25 to establish a driving connection between the shaft l9 and an annulus gear 29 which forms part of a planetary gearset 30.

The planetary gearset 30 is adapted to transmit selectively variable drive from the shaft i9 to the shaft 3| and is under the control of suitable control mechanism which is immaterial to the present invention and which is fully described and illustrated in the aforesaid Neracher et al. application, Serial No. 271,016 of which this application is a continuation-in-part.

From the description of the apparatus so far,

it is apparent that rotation of the engine crankshaft 10 will cause rotation of the impeller [2 of the fluid coupling A thereby causing circulation of the fluid therein for transmitting a slip drive to the runner i! which drive will be transmitted to the vehicle driving wheels through the hub l8, shaft l9, clutch 28, planetary gearset and shaft 3i.

Carried on the transmission housing 32 and suitably fastened thereto is a starting motor 33 which may be of any suitable type. Motor 33 is provided with a shaft 34 which carries a pinion 35 adapted for meshing engagement with a ring gear 36 carried by the clutch spider 26 as illustrated in Fig. 1. The ring gear 38 may be attached to the clutch spider 26 by any suitable means such as shrinking or welding. The motor 33 is adapted for control by a suitable control means such as that well-known in the art and the pinion 35 may be provided with an overrunning clutch device to permit overrun during normal driving of the vehicle by the crankshaft H) or if desired, suitable disengaging means may be provided for the pinion 35 such as that known in the art as the Bendix Drive.

Motor 33 when energized transmits a drive to the crankshaft i0 through shaft 34, pinion 35, ring gear 36, clutch spider 26, shaft l9, hub l8, fluid coupling runner I6 and fluid coupling impeller 12. The drive thus transmitted is a slip drive, the runner IE temporarily becoming the driving member of the fluid coupling A. Because of the fact that the starting torque is transmitted from the motor 33 through the fluid coupling A, the usual shocks incident to starting of a heavy internal combustion engine such as that commonly provided in motor vehicles are cushioned and absorbed in the fluid coupling. A further advantage resides in the fact that at the instant of starting, the motor 33 is required to initially rotate only the fluid coupling runner i6 and the associated driving apparatus between the motor and runner and thus the motor 33 is enabled to impart substantial rotational speed to the runner l6 before the crankshaft [0 begins to turn. This is due to the well-known slipping characteristics of the fluid coupling and enables easier starting of the engine than is the case when the starting motor is connected directly to the engine such as is usual in the art; under which conditions, the starting motor is required to overcome the static friction incident to initially rotating the crankshaft of the motor which results in heavy withdrawal of current from the vehicle battery with consequent reduction in the life thereof.

With the starting system just described, the parts thereof may be considerably lightened and of more economical manufacture due to the fact that the starting system is not required to absorb severe shocks and the starting motor is enabled to attain considerable speed before full load is imposed thereon.

Fig. 2 illustrates a modification of the invention wherein an overrunning clutch generally referred to by the letter B is interposed between the starting motor 33' and the crankshaft in for establishing a direct driving connection therebetween.

In Fig. 2 the fluid coupling A is in general similar to that shown in Fig. 1 and has the usual vaned impeller member. i2 and a varied runner member l6 for transmitting drive from the crankshaft Hi to the vehicle driving shaft 3| through hub member [8, shaft l9, clutch 28, the spider 26' of which is splined on the shaft l9 at 21', shaft 31 and change speed gearing 38.

The clutch spider 26' forms the driving member of a friction clutch generally referred to at 28' which has a driven mat 39 splined to the shaft 31 at 40 and a release mechanism 4| which is adapted for operation by a clutch pedal (not shown) or other suitable means. As may be readily understood, the shaft 31 is adapted to receive a slip drive from the crankshaft if! when the clutch 28' is in engaged .position as is shown in Fig. 2 with said drive being transmitted to the transmission mechanism 38 for driving the vehicle. Release of the clutch 28 will release the drive between the shafts l9 and 31 to facilitate shifting gears in the mechanism 38 and for other purposes.

The clutch spider 26' carries a ring gear 36' which is adapted to mesh with the pinion 35 carried by the shaft 34' of starting motor 33.

The overrunning clutch B which is more clearly illustrated in Fig. 3 is of the well-known cam and roller type and has rollers 42 which are held in spaced relation by a carrier 43. The extreme forward portion of the'hub i8 is provided with a plurality of cam surfaces 44 which cooperate with the rollers 42 to wedge the same into driving relationship with the internal cylindrical surface 45 of the crankshaft l0 upon tendency of the hub I8 to rotate faster in a forward (clockwise) directionthan the crankshaft ID' while permitting overrun of the crankshaft ifl when it tends to run faster than the hub [8.

In order to provide the desired rigidity for the hollow portion of the hub I8 in the vicinity of the overrunning clutch B and at the same time seal this hub against the escape of the coupling fluid, a cylindrical plug 46 has been inserted by means of a press fit in the extreme forward end portion of the hub [8 adjacent the forward end of the shaft 31 and within the hollow end portion 22 of the crankshaft 10.

Because of the slipping characteristics of the fluid coupling A, the crankshaft l0 will, of course, always drive faster than the shaft I9 in transmitting drive to the shaft 31. The slip is very small at high engine speeds but is at all times sufficient to produce overrun at the overrunning clutch B whenever the engine is driving the vehicle. Thus it may be seen that the overrunning clutch B does not in any way efiect the normal slip characteristics of the fluid coupling.

It will therefore readily be seen that upon energization of starting motor 33', the drive will be transmitted to the crankshaft l0 through ring gear 36, clutch driving spider 26, shaft l9 and overrunning clutch rollers 42. This drive will be a direct or I to I drive and the fluid coupling itself will be bridged, thereby eliminating slip between the shaft I9 and the crankshaft l0. While this arrangement diflers from the arrangement shown in Fig. 1 in that the slipping characteristics of the fluid coupling are not availed of for starting the engine, it does offer distinct advantages over arrangements now used in the art in that it permits the starting motor 33 and its associated mechanism to be positioned at a more convenient position on the vehicle.

While in both Figs 1 and 2 the starting motor has been illustrated mounted on the top of the transmission casing, it is desired to point out that this has been done for the convenience of illustration only and the normal position of the starting motor would probably be on the side of the transmission casing preferably below the axis of the crankshaft where there is available space which is normally not used in the ordinary motor vehicle.

While each of the forms of our invention has been illustrated in combination with specific vehicle driving apparatus, it is obvious that our invention is not limited to the particular apparatus shown and described. It is equally obvious that the overrunning clutch B illustrated in connection with the Fig. 2 modification can readily be used in the Fig. 1 modification if desired and may be omitted in the Fig. 2 modification if it is desired to utilize the slipping characteristics of the fluid coupling in starting the vehicle engine. Various other changes and modifications in the apparatus shown and described herein for the purpose of illustration will readily be apparent to those skilled in the art and it is not desired to limit the invention in its broader aspects to the arrangements shown and described herein, the scope thereof being defined in the claims appended hereto.

We claim:

1. A vehicle drive mechanism comprising in combination, an engine, a fluid impeller adapted to be driven by said engine, a fluid runner disposed in driving relationship with said impeller,

'a main vehicle clutch including a clutch member adapted to be driven by said runner, and an engine starting device including a prime mover carried by the vehicle adapted for driving connection with said clutch member.

2. In a power plant including an engine and a flywheel, a fluid coupling interposed in the driving connection between said engine and flywheel, the impeller of said coupling being connected to said engine and the runner thereof being connected to said flywheel; a ring gear carried drive shaft, a driven shaft; a fluid coupling includingdriving and driven members connecting said shafts and adapted to transmit a slip drive therebetween, upon rotation of said driving member at a greater speed than said driven member; a one-way clutch operatively connecting said shafts and adapted to permit said drive shaft to overrun said driven shaft while automatically operable to establish a direct driving connection between said shafts upon tendency of said driven shaft to overrun said drive shaft, and an engine starting device including a prime mover adapted for connection to said driven shaft.

by said flywheel and an engine starting motor assembly including a drive pinion adapted for engagement with said ring gear whereby starting torque from said motor is transmitted to said engine through said coupling.

3. In combination with a vehicle power plant including an engine, a transmission mechanism, and a fluid coupling for connecting the engine and transmission mechanism; releasable clutch means interposed between said fluid coupling and transmission mechanism including a driving member; an engine starting device, and means for drivingly connecting said device to said clutch driving member whereby starting ...t01q1 isadapted to be transmitted to said engine through said fluid coupling.

4. In combination with an engine having a 5. In a drive for a motor vehicle having an engine provided with a crankshaft, a fluid coupling comprising impeller and runner structures; means for connecting the impeller structure with the crankshaft, means for transmitting drive from .the runner structure to the vehicle; an overrunning clutch operable between said structures to prevent rotation of the crankshaft at a speed below that of the runner structure and an engine starting device including a prime mover carried by the vehicle adapted for connection to said runner structure.

6. In a drive for a motor vehicle having an engine provided 'iivith a "crankshaft, a fluid coupling comprising impeller and runner struc tures; means for connecting the impeller structure with the crankshaft, means for transmitting drive from the runner structure to'the vehicle; an overrunning clutch operable between said structures to prevent rotation of the crankshaft at a speed below that of the runner structure; a clutch including a driving spider connected to said runner structure and an engine starting device including a prime mover adapted for connection to said spider.

'7. In a drive for a motor vehicle having an engine and a shaft adapted to drive the vehicle, an overrunning clutch operable to establish direct drive connection from said shaft to said engine to prevent the engine from dropping in its speed below the rotational speed of said shaft; a fluid coupling for transmitting'a slip drive from the engine to said shaft by bridging said overrunning clutch; said clutch automatically acting to release said drive connection in response to accelerating the engine above the speed of said shaft thereby accommodating drive of said shaft by said coupling; a tailshaft; selectively operable means for establishing forward or reverse drive connection of said tailshaft with said shaft; a gear carried by said shaft, and a prime mover adapted for connection with said gear whereby said engine is adapted to be started through said overrunning clutch, said clutch bridging said fluid coupling during operation of said, device.

8. In combination with a motor vehicle power plant including a crankshaft, a fluid impeller carried by said crankshaft; a fluid runner dis posed in juxtaposition relative to said impeller; a clutch driving plate carried by said runner; a starting motor carried by the vehicle, and means for drivingly coupling said starting motor to said clutch driving plate.

CARL A. NERACHER. WILLIAM T. DUNN. 

